• R N Singhal

      Articles written in Proceedings – Animal Sciences

    • Effect of temperature on consumption, digestion and utilization of food inPoecilocerus pictus Fabr. (Orthoptera : Acrididae)

      R N Singhal

      More Details Abstract Fulltext PDF

      The effect of temperature and starvation on the consumption, digestion and utilisation of food inPoecilocerus pictus Fabr. was investigated. Adult male when supplied with fresh leaves ofCalotropis procera R. Br., after 0, 6, 12, 18, 24 hr of starvation, attained maximum weights of 446±14 to 613±29 mg at all temperature under present study, while in female the maximum weights were 999±6 to 1726±3 mg. With increasing temperature the rates of consumption, digestion and utilisation increased; however, the insects died at 39° C. Feeding rates which did not differ significantly in males and females, varied from 20±4 to 1801±116 mg g−1 day−1. Assimilation efficiency increased from 51·6±1% at 15° C to 84·2±4·8% at 30°C and then decreased to 47·9% from 33°C to 36°C. Conversion efficiency varied from 8·0±7% to 41·8±9% at different temperatures. Ecological growth efficiency was maximum at 27° C.

    • The annual reproductive cycle ofAchaetohonellia maculata Fisher (Echiura: Bonellidae)

      R N Singhal

      More Details Abstract Fulltext PDF

      This study is the first to detail the annual reproductive cycle of any echiuran. Here the annual reproductive cycle ofAchaetohonellia maculata Fisher is described. Oocytes first appear in the coelomic fluid in late spring or early-summer. During fall and winter, gametes production and differentiation continue. Differentiation of gametes lasts four to six months. Spawning occurs in spring. Since the niaks are the permanent residents in the gone duct of the female, the fertilization is internal in Boneliidae. Temperature of the sea water probably is the most important exogenous factor controlling the reproductive cycle. Individuals reach sexual maturity when they are one year old.

    • Ectoparasites of the freshwater food fishes of Haryana

      R N Singhal Swarn Jeet R W Davies

      More Details Abstract Fulltext PDF

      This communication records eight ectoparasites of the gills and skin from edible freshwater fishes of Haryana. Since all eight parasites collected differ from those described earlier in the literature, they are briefly redescribed and arranged systematically.

    • The physico-chemical environment and the plankton of managed ponds in Haryana, India

      R N Singhal Swarn Jeet R W Davies

      More Details Abstract Fulltext PDF

      An investigation was made of the physical, chemical conditions of the water and substrate of nursery-cum-research-cum-rearing-cum-stocking ponds at Central Inland Fisheries Research Institute, Karnal. Temperature, pH, CO2, dissolved oxygen, chloride, phosphate, alkalinity, nitrates, organic matter, total solids, turbidity, electric conductivity, nitrogen, P2O5, sand, silt, clay, CaCO3, etc. were measured monthly. Statistical analysis of these factors showed some significant correlations. The phyto- and zooplankton were also sampled and the seasonal changes in abundance recorded.

  •  

© 2021-2022 Indian Academy of Sciences, Bengaluru.